1. Technical Field
The present invention relates to a work transporting apparatus of a transfer press which includes a work transporting apparatus for feeding works into a press body and a transfer feeder for sequentially transporting works into respective processing stations in the press body.
2. Description of the Related Art
Conventionally, in a transfer press having a plurality of processing stations in a press body, a transfer feeder for sequentially transporting works to respective processing stations is provided.
Furthermore, on the upstream side of the press body, a disc stacker for separating stacked works one by one, is arranged. The work separated by the disc stacker is fed into the press body by a work transporting apparatus, and is subsequently transported into respective processing stations by the transfer feeder to be shaped in the respective processing stations.
The transfer feeders are arranged within the press body and are operable to transport the works into the respective processing stations. The transfer feeders are disclosed in Japanese Unexamined Patent Publication (Kokai) No. Heisei 6218459 and Japanese Unexamined Patent Publication No. Heisei 6-262280, for example.
The transfer feeder disclosed in the former publication has a pair of lifting beams extending in a feeding direction, which is vertically movable by a lift mechanism. A plurality of cross-bar carriers are supported on the lifting beams. The cross-bar, carriers are connected to each other and are reciprocally moved in the feeding direction by a feed mechanism arranged at the upper portion on an upstream side of the press body. In conjunction therewith, a cross-bar having a work suction means is transversely extended between adjacent cross-bar carriers. Then, the lift mechanism and the feed mechanism are arranged at the upper portion on the press body.
While the transfer feeder disclosed in the later publication has substantially the same construction as the transfer feeder disclosed in the former publication, the feed mechanism is arranged at the lower portion on an upstream side or a downstream side of the press body.
Meanwhile, in all of the conventional transfer feeders, while a lifting operation of the cross-bars is performed by the lift mechanism taking a servo motor as a driving source, and a feeding operation thereof is performed by the feed mechanism driven by the driving power taken from the press body, another driving source is employed for a work carrying-in or delivery apparatus which feeds the works into the press body. Thus, due to separate systems, the overall driving system becomes quite complicated and expensive.
On the other hand, in the case of the transfer feeder disclosed in the foregoing publication, because of a structure, in which the feed mechanism is directly coupled with the slide driving mechanism, there is no space between the slide driving mechanism and the feed driving mechanism to arrange a clutch which is necessary for solely driving the transfer feeder. Furthermore, since the feed mechanism projects from the front side of the press body, problems are encountered in that an upper frame becomes large and complicated, and, the crane may interfere with the foregoing feed mechanism upon exchanging dies, thus a wide space is necessary for locating the die exchanging position distant from the press body so as to avoid interference is required.
Furthermore, because of the construction in which the driving source of the lift mechanism is arranged at the upper portion on the upstream side or the downstream side of the press body and the respective lifting rods are driven up and down by the driving source, an equalizer means for establishing a synchronization of the respective lifting rods becomes necessary, thus making the construction complicated. Furthermore, vibration of the lifting rods and so forth may be amplified by play caused in the equalizer means and may be a cause of noise and mis-feeding. In addition, since a large size and large capacity servo motor is required, the apparatus becomes expensive.
On the other hand, in the transfer feeder disclosed in the later publication, since the feed mechanism is placed at the lower portion of the press body, it may interfere with installation of the work carrying-in apparatus when the feed mechanism is located on the upstream side, and in an installation of a product feeding out apparatus when the feed mechanism is located on the downstream side.
The present invention is provided to improve the drawbacks set forth above, and therefore, it is an object of the present invention to provide a work transporting apparatus of a transfer feeder, which can drive the work feeding apparatus and the transfer feeder with a common driving system so as to simplify of the driving system and lowering costs.
On the other hand, as the work carrying-in apparatus for feeding the work into the press body, the apparatus shown in FIG. 1, has been employed, for example.
Namely, the work "b", separated one-by-one by a destacker "a" is washed by a washing apparatus "c" and thereafter transported into a centering apparatus "e" by a belt feeder "d" to be positioned at a predetermined position.
On the upper portion of centering apparatus "e" a carrier of the work carrying-in apparatus "f" is provided in movable fashion in a feeding direction (arrow A). The carrier "g" is connected to the lower end of a rocking lever "h" via a link "i".
The rocking lever "h" is pivotally connected to an apparatus body at the upper end thereof so that it may be swung in synchronism with an operation of the press body "i" by means of a cam "k" rotated by a driving power taken from the press body "j". By this, the foregoing carrier "g" is reciprocally driven in the feed direction A.
Furthermore, at the lower portion of the carrier "g", a work supporting arm "m" is projected. On the tip end of the work supporting arm "m", a work suction means "n" like a vacuum cap is provided. The arrangement is so constructed that when the suction means "n" sucks the work "b" positioned by the centering device, the work "b" is lifted up by an elevation of a lifting beam "p" to the position shown by the phantom line in FIG. 1 by a lifting drive device "q", and then fed into a press body "j" by a movement of the carrier "g".
In the meantime, in the foregoing conventional work carrying-in apparatus, since the rocking lever "h" is pressed onto a cam "k" by a reaction cylinder "o" the cam "k" has to cause rocking motion of the rocking lever "h" against the force of the reaction cylinder "o" requiring a large driving torque which causes a large power consumption. Also, since it is required to accommodate the reaction cylinder "o" or a large diameter air piping in the cam box, the cam box becomes bulky and makes the overall apparatus expensive.
On the other hand, because of a structure, in which the rocking lever "h" and the carrier "g" are connected by means of a link "i" an angle of the link "i" is varied when a height of the carrier "g" is varied due to variation of a work transportation height (path line). As a result, when the work "b" is sucked and elevated to the path line, the carrier "g" may be rocked in the feeding direction as shown by the broken line in FIG. 2 to possibly cause a mis-feeding due to a falling down of the sucked work "b".
In order to improve such drawbacks, a long length is provided for the link in the prior art so that the angle of the link does not vary significantly even when the path line is varied. When a longer length is provided for the link "i", a positional relationship between the rocking lever "h" and the carrier "g" is restricted, or the rocking lever "h" is arranged on the upstream side to make the overall apparatus bulky.
Another purpose of the present invention is to improve the above drawbacks. It is therefore an object of the present invention to provide a work carrying-in or delivery apparatus of a transfer feeder which is not influenced by variations of a path line and can be driven by a smaller driving force.